Method For Controlling a Blood Component Separation Device Including Temporarily Storing a Component in a Container

ABSTRACT

The object of the invention is to provide a blood separation device that can reduce the total time for drawing blood to obtain high-concentration platelet liquid, thereby reducing the binding time of the blood donor. The device includes a temporary storage bag (Y 2 ) (also serves as a buffy coat bag) which is a whole blood bag for storing whole blood drawn from a blood donor. The controlling unit of the device controls the device to draw whole blood from the blood donor in parallel with at least either a circulation flow step or an acceleration step, thereby storing the drawn whole blood in the temporary storage bag (Y 2 ).

TECHNICAL FIELD

The present invention relates to a blood component separation deviceincluding a centrifugal separator for separating a predetermined bloodcomponent from blood and a container for containing the centrifugallyseparated predetermined blood component.

BACKGROUND ART

Conventionally, in the field of blood drawing, a blood component such asplatelets is collected by collecting only the component from drawn bloodand returning the remaining blood components to the blood donor. In suchoperation, a blood component separation device including a centrifugalseparator is used.

In recent years, in the field of radiation therapy of cancer or thelike, transfusion of platelet liquid is widely performed, andhigh-concentration platelet liquid is necessary. To obtainhigh-concentration platelet liquid, Patent Literature 1 discloses an artusing a blood component separation device to temporarily storelow-concentration platelet liquid in a buffy coat bag and store onlyhigh-concentration platelet liquid in a platelet intermediate bag. Thus,from the centrifugal separator, the low-concentration platelet liquidflows out first, then the high-concentration platelet liquid flows out,and finally the low-concentration platelet liquid flows out. When thelow-concentration platelet liquid, which flows out first and last, isstored in the platelet intermediate bag, the concentration of theplatelet liquid stored in the platelet intermediate bag inevitablydecreases. To prevent the decrease in concentration, thelow-concentration platelet liquid that flows out first and last istemporarily stored in the buffy coat bag. Then in the second cycle, thetemporarily stored low-concentration platelet liquid is mixed with wholeblood drawn from the blood donor and transferred to the centrifugalseparator. By repeating this process, only high-concentration plateletliquid is stored in the platelet intermediate bag.

CITATION LIST Patent Literature

Patent Literature 1: JP 3850429 B1

Patent Literature 2: JP 2009-226210 A

SUMMARY OF INVENTION Technical Problem

The technique disclosed in Patent Literature 1 however has disadvantageas described below. The disadvantage is that when blood drawing isperformed to collect a blood component, three or four cycles of blooddrawing are required to collect a predetermined amount ofhigh-concentration platelet liquid because the amount ofhigh-concentration platelet liquid collected in one cycle is as small asa few tenths of millimeters. A blood donor is thus kept bound for a longtime to draw blood. This gives stress to a busy blood donor. Anotherdisadvantage is that, although a busy blood donor prefers drawing of ablood component, the blood donor cannot but choose the drawing of wholeblood.

The invention is made in view of the aforementioned problem. The objectof the present invention is to provide a blood component separationdevice that, when drawing blood to collect high-concentration plateletliquid, can reduce the total time of collecting whole blood, therebyreducing the binding time of a blood donor.

Solution to Problem

To achieve the object, a blood component separation device according toone aspect of the present invention is configured as described below.

(1) A blood component separation device includes a centrifugal separatorfor separating a predetermined blood component from blood and acontainer for containing the centrifugally separated predetermined bloodcomponent, and performs (a) centrifugal separation step of introducingthe whole blood drawn from a blood donor into the centrifugal separatorwith a first blood pump and separating the whole blood into a pluralityof blood components, (b) circulation flow step of introducing thepredetermined first blood component, among centrifugally separated bloodcomponents, stored in a first container into the centrifugal separatortogether with whole blood, (c) circulation/acceleration step of stoppingthe supply of whole blood to the centrifugal separator after separatinga predetermined amount of the first blood component in the circulationflow step, introducing only the first blood component stored in thefirst container to the centrifugal separator with the second blood pumpto circulate the first blood component for a predetermined period oftime, and increasing the circulation speed in the centrifugal separatorto separate and collect a second blood component. The blood componentseparation device is characterized in that the whole blood drawn fromthe blood donor is temporarily stored in a temporary storage containerduring at least a period in the circulation/acceleration step, and oneof tubes coupled to the temporary storage container is coupled to anoutlet port of the centrifugal separator and the other tube is coupledbetween the first container and a second blood pump.

(2) The blood component separation device according to (1) is preferablycharacterized in that the second blood pump introduces, in thecentrifugal separation step in the following cycle, at least either thewhole blood or the low-concentration second blood component stored inthe temporary storage container in the previous cycle into thecentrifugal separator.

In this manner, at least either the whole blood or the low-concentrationsecond blood component stored in the previous cycle can quickly andsurely be introduced into the centrifugal separator.

(3) The blood component separation device according to (1) or (2) ispreferably characterized in that the other tube is branched to becoupled to an outlet port of a first blood pump, an open/close valve isprovided on each of two tubes branched from the other tube, anopen/close valve is provided to an outlet port of the second blood pump,and an open/close valve is provided to an outlet port of the firstcontainer.

In this configuration, at least either the whole blood or thelow-concentration second blood component stored in the temporary storagebag can be introduced into the centrifugal separator by using the secondblood pump without any additional blood pump, and thus the device neednot be large in size, and the cost can be reduced. Furthermore, comparedto a device using a difference in elevation instead of a blood pump, atleast either the whole blood or the low-concentration second bloodcomponent stored in the temporary storage bag Y2 can be introduced intothe centrifugal separator E1 in a short time by using the blood pump.

(4) The blood component separation device according to any one of (1) to(3) preferably performs (d) blood returning step, which is performedafter collecting the predetermined amount of the second blood componentin the circulation/acceleration step, of returning to the blood donorthe blood component that is not collected, and is characterized in thatthe whole blood stored in the temporary storage container is introducedinto the centrifugal separator in the centrifugal separation step of thefollowing cycle together with the whole blood drawn in the followingcycle, where the steps (a) to (d) constitute one cycle.

In this configuration, in parallel with the circulation/accelerationstep in the first cycle (the present cycle), whole blood can be drawnfrom the blood donor, so that the time of drawing whole blood in thesecond cycle (the following cycle) can be reduced, thereby reducing thetotal time of the process and the binding time of the blood donor.

For example, typical time periods in one cycle are nine minutes forblood drawing and the circulation flow step (critical flow step), 30 to40 seconds for the circulation step in the circulation/accelerationstep, 20 to 30 seconds for the acceleration step in thecirculation/acceleration step, and about four minutes for the bloodreturning. According to the present invention, since blood drawing isperformed for about one minute in the first cycle, the blood drawingtime in the second cycle can be reduced by one minute to about eightminutes. Similarly, when total of three cycles are performed, the blooddrawing time in the third cycle can be reduced by one minute to abouteight minutes.

For a blood donor, the amount of blood circulating outside the bodyincreases, though it may not be a problem for 90% of blood donors. Thedonor may be checked in advance to see if there is a problem to increasethe amount of blood circulating outside the body. If there may be aproblem, a switching unit can be used so as not to perform the drawingof whole blood in parallel with the circulation/acceleration step in thefirst cycle (the present cycle), but to perform the drawing of wholeblood in the second cycle (the following cycle) after returning blood.It goes without saying that the drawing of whole blood for the followingcycle is not performed in the last cycle, because there is no cyclefollowing the last cycle.

(5) The blood component separation device according to any one of (1) to(4) is preferably characterized in that the circulation/accelerationstep includes a first collecting step of transferring a portion of thesecond blood component with low-concentration to a temporary storagecontainer and a second collecting step of collecting a portion of thesecond blood component with high-concentration, and that thelow-concentration second blood component transferred to the temporarystorage container and the whole blood collected in the temporary storagecontainer in the following cycle are introduced into the centrifugalseparator together with whole blood drawn in the following cycle.

In this configuration, the BC recycling for obtaining high-concentrationplatelets can be used and, along with the circulation/acceleration stepin the first cycle (the present cycle), the whole blood can be drawnfrom the blood donor, so that the time of drawing whole blood in thesecond cycle (the following cycle) can be reduced, thereby reducing thetotal time of the process and the binding time of the blood donor.

(6) The blood component separation device according to (5) preferablyincludes a second container for temporarily storing thelow-concentration second blood component in the circulation/accelerationstep, and is characterized in that the second container also serves asthe temporary storage container.

In this configuration, an additional second container is not required sothat the device need not be made large in size, and since a specialdisposable second container is not required, the cost can be reduced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a configuration of a blood component separationdevice according to a first working example of the present invention.

FIG. 2 illustrates a first step (starting blood drawing step) of theblood component separation device according to the first working exampleof the present invention.

FIG. 3 illustrates a second step (centrifugal separation step).

FIG. 4 illustrates a third step (critical flow step).

FIG. 5 illustrates a circulation step in a fourth step(circulation/acceleration step).

FIG. 6 illustrates a step of collecting low-concentration plateletliquid performed in the fifth step (circulation/acceleration step).

FIG. 7 illustrates a step of storing high-concentration platelet liquidperformed in the fifth step (circulation/acceleration step).

FIG. 8 illustrates a step of collecting low-concentration plateletliquid performed in the fifth step (circulation/acceleration step).

FIG. 9 illustrates a blood returning step.

FIG. 10 illustrates the first step performed in a second cycle.

FIG. 11 illustrates the second step performed in the second cycle.

FIG. 12 illustrates the third step performed in the second cycle.

FIG. 13 illustrates a processing step of platelet liquid.

FIG. 14 illustrates a final processing step of platelet liquid.

FIG. 15 illustrates a structure of a centrifuge bowl.

FIG. 16 illustrates an operation of the blood component separationdevice in a chronological order.

FIG. 17 illustrates changes in concentrations of platelets, white bloodcells, and red blood cells flowing out.

FIG. 18 is a flow chart illustrating an operation of the blood componentseparation device.

FIG. 19 is a flow chart illustrating an operation performed in acollecting step of collecting platelet liquid.

FIG. 20 is a block diagram illustrating a control system of the bloodcomponent separation device according to an embodiment.

DESCRIPTION OF EMBODIMENTS

FIG. 1 illustrates a system configuration of a blood componentseparation device according to the present invention. FIG. 20 is a blockdiagram illustrating a control system of the blood component separationdevice according to an embodiment.

The blood component separation device according to the embodimentincludes a blood component separation circuit 1. The blood componentseparation circuit 1 includes an initial flow blood collecting circuit 5composed of a blood drawing needle 2, an initial flow blood collectingbag Y7 for collecting initial flow blood, a sampling port 3, and aninitial flow blood collecting line 4. The blood component separationcircuit 1 includes a centrifuge bowl E1. The centrifuge bowl E1 includesa rotor (not shown) having therein a space for storing drawn blood, arotor drive unit 14 for rotating the rotor, an inflow port (first portE1 a), and an outflow port (second port E1 b), and is configured toseparate blood into a plurality of blood components by rotating therotor. The blood component separation circuit 1 includes threecontainers for storing blood components separated in the centrifuge bowlE1, that is, a first container (plasma bag) Y1, a second container(temporary storage bag) Y2, and a third container (platelet intermediatebag) Y3. The blood component separation circuit 1 includes a first line,a second line, a third line, a fourth line, a fifth line, a sixth line,and a seventh line. The first line couples the blood drawing needle 2and the centrifuge bowl E1 and includes a donor tube T1, a first bloodpump P1, a tube T2, a tube T3 a, a first open/close valve V1, a tube T3b, and a tube T4. The second line couples the centrifuge bowl E1 and thefirst container Y1 and includes a tube T5, a tube T6 a, a secondopen/close valve V2, and a tube T6 b. The third line couples the firstcontainer Y1 and the first line and includes a tube T8 a, a thirdopen/close valve V3, a tube T8 b, a tube T9, a second blood pump P2, atube T10 b, a fourth open/close valve V4, and a tube T10 a. The fourthline couples the centrifuge bowl E1 and the second container Y2 andincludes a tube T5, a tube T15, a tube T11 a, a fifth open/close valveV5, and a tube T11 b. The fifth line couples the second container Y2 andthe first line and includes a tube T12, a tube T13 b, a sixth open/closevalve V6, and a tube T13 a. The sixth line couples the second containerY2 and the first line, similarly to the fifth line, and includes a tubeT12, a tube T14 a, a seventh open/close valve V7, a tube T14 b, a tubeT9, the second blood pump P2, the tube T10 b, the fourth open/closevalve V4, and the tube T10 a. The seventh line couples the centrifugebowl E1 and the third container Y3 and includes the tube T5, the tubeT15, a tube T16, a tube T17 a, an eighth open/close valve V8, and a tubeT17 b.

The blood drawing needle 2 for drawing whole blood (blood) from a blooddonor is coupled to the first port of the first blood pump P1 via thedonor tube T1. The initial flow blood collecting bag Y7 is coupled tothe blood drawing needle 2 via a branch provided on the donor tube T1and via the initial flow blood collecting line 4. The initial flow bloodcollecting bag Y7 includes a sampling port 3 for transferring collectedinitial flow blood to a test container (not shown). The sampling port 3is constituted with a main body, a needle 6, and a cover 7 for coveringthe needle. Further, a clamp 8 is provided on the initial flow bloodcollecting line to open/close the line.

The tube T2 coupled to the second port of the first blood pump P1 isbranched into the tube T3 a and the tube T13 a. The tube T3 a is coupledto the first port of the first open/close valve V1, and the second portof the first open/close valve V1 is coupled to the tube T3 b. The tubeT3 b is branched into the tube T4 and the tube T10 a. The tube T4 iscoupled to the first port E1 a of the centrifuge bowl E1, which is acentrifugal separator for separating collected blood into a plurality ofblood components. The centrifuge bowl E1 is disposed on the rotor driveunit 14 to be rotated.

The blood drawing needle 2 and the first port E1 a, which is an inletport of the centrifuge bowl E1, are coupled via the first line (thedonor tube T1, the first blood pump P1, the tube T2, the tube T3 a, thefirst open/close valve V1, the tube T3 b, and the tube T4). A pressuresensor C1 is coupled to the donor tube T1.

The tube T5 coupled to the second port E1 b of the centrifuge bowl E1 isbranched into the tube T15 and the tube T6 a. The tube T6 a is coupledto the first port of the second open/close valve V2, and the second portof the second open/close valve V2 is coupled to the tube T6 b. The tubeT6 b is coupled to the second port Y1 b of the plasma bag (the firstcontainer) Y1.

The second port E1 b of the centrifuge bowl E1 and the plasma bag Y1 arecoupled via the second line (the tube T5, the tube T6 a, the secondopen/close valve V2, and the tube T6 b). Two plasma bags Y1 areprovided, though only one plasma bag Y1 is illustrated in FIGS. 2 to 14.

A first port Y1 a, or the outlet port, of the plasma bag Y1 is coupledto the tube T8 a. The tube T8 a is coupled to the first port of thethird open/close valve V3. The second port of the third open/close valveV3 is coupled to the tube T8 b, and the tube T8 b is coupled to the tubeT9. The tube T9 is coupled to the second port of the second blood pumpP2. The first port of the second blood pump P2 is coupled to the tubeT10 b, and the tube T10 b is coupled to the second port of the fourthopen/close valve V4. The first port of the fourth open/close valve V4 iscoupled to the tube T10 a. The tube T10 a is coupled to the intermediateposition between the tube T3 b and the tube T4 constituting the firstline. The plasma bag Y1 and the first line are coupled via the thirdline (the tube T8 a, the third open/close valve V3, the tube T8 b, thetube T9, the second blood pump P2, the tube T10 b, the fourth open/closevalve V4, and the tube T10 a). The plasma bag Y1 is thus configured toselectively communicate with the inlet port or the outlet port of thecentrifuge bowl E1.

The tube T15 branched from the tube T5 branches into the tube T11 a andthe tube T16. The tube T11 a is coupled to the first port of the fifthopen/close valve V5, and the second port of the fifth open/close valveV5 is coupled to the tube T11 b. The tube T11 b is coupled to the secondport Y2 b of the temporary storage bag Y2 via the tube T11 b. That is,the second port E1 b of the centrifuge bowl E1 and the temporary storagebag Y2 are coupled via the fourth line (the tube T5, the tube T15, thetube T11 a, the fifth open/close valve V5, and the tube T11 b).

The first port Y2 a of the temporary storage bag Y2 is coupled to thetube T12, and the tube T12 is branched into the tube T13 b and the tubeT14 a. The tube T13 b is coupled to the first port of the sixthopen/close valve V6, and the second port of the sixth open/close valveV6 is coupled to the tube T13 a. The tube T13 a is coupled to theintermediate position between the tube T2 and the tube T3 a constitutingthe first line.

The tube T14 a branched from the tube T12 is coupled to the first portof the seventh open/close valve V7, and the second port of the seventhopen/close valve V7 is coupled to the tube T14 b. The tube T14 b iscoupled to the intermediate position between the tube T9 and the tube T8b, and the tube T9 is coupled to the second port of the second bloodpump P2. The first port of the second blood pump P2 is coupled to thetube T10 b, and the tube T10 b is coupled to the first port of thefourth open/close valve V4. The second port of the fourth open/closevalve V4 is coupled to the tube T10 a. The tube T10 a is coupled to theintermediate position between the tube T3 b and the tube T4 constitutingthe first line.

The temporary storage bag Y2 and the first line are coupled via thefifth line (the tube T12, the tube T13 b, the sixth open/close valve V6,and the tube T13 a) and the sixth line (the tube T12, the tube T14 a,the seventh open/close valve V7, the tube T14 b, the tube T9, the secondblood pump P2, the tube T10 b, the fourth open/close valve V4, and thetube T10 a). The temporary storage bag Y2 is coupled so as toselectively communicate with the inlet port or the outlet port of thecentrifuge bowl E1.

The tube T16 branched from the tube T15 branches into the tube T17 a andthe tube T18 a. The tube T17 a is coupled to the first port of theeighth open/close valve V8, and the second port of the eighth open/closevalve V8 is coupled to the tube T17 b. The tube T17 b is coupled to thefirst port Y3 a, which is the inlet port of the platelet intermediatebag (the third container) Y3.

The tube T18 a branched from the tube T16 is coupled to the first portof the ninth open/close valve V9, and the second port of the ninthopen/close valve V9 is coupled to the tube T18 b. The tube T18 b iscoupled to the air bag Y4.

The second port E1 b of the centrifuge bowl E1 and the plateletintermediate bag Y3 are coupled via the seventh line (the tube T5, thetube T15, the tube T16, the tube T17 a, the eighth open/close valve V8,and the tube T17 b). The platelet intermediate bag Y3 is thus configuredto communicate with the outlet port of the centrifuge bowl E1.

A turbidity sensor C2 for detecting the concentration of platelets andthe pressure sensor C3 are attached to the tube T5 coupled to the secondport E1 b of the centrifuge bowl E1. The turbidity sensor C2 detects theturbidity, caused by platelets, of plasma flowing in the tube T5. In theperipheral region of where the centrifuge bowl E1 is provided, aninterface sensor C4 for detecting the location of the interface of abuffy coat layer BC (see FIG. 15) formed in the centrifuge bowl E1 isattached.

The tube T19 extending from the second port Y3 b, or the outlet port, ofthe platelet intermediate bag Y3, is branched into the tube T20 a andthe tube T21. The tube T20 a is coupled to the first port of the tenthopen/close valve V10, and the second port of the tenth open/close valveV10 is coupled to the tube T20 b. The tube T21 is coupled to the firstport of the third blood pump P3, which is the output port.

The second port, or the input port, of the third blood pump P3 iscoupled to a platelet reserve liquid bottle via a sterilizing filter 9and a bottle needle 10. The tube T20 b is coupled to the platelet bag Y5via a white blood cell removal filter 11. The air bag Y6 is coupled tothe platelet bag Y5.

An output port of the ACD pump P4 is coupled to the donor tube T1. Theinput port of the ACD pump P4 is coupled to the output port of thesterilizing filter 12. The input port of the sterilizing filter 12 iscoupled to the ACD storing bottle via a bottle needle 13.

As illustrated in FIG. 20, a controller 15 is configured with, forexample, a microcomputer. The controller 15 is electrically coupled tothe first blood pump P1, the second blood pump P2, the third blood pumpP3, the ACD pump P4, the centrifuge bowl drive unit 14, the pressuresensor C1, the turbidity sensor C2, the pressure sensor C3, theinterface sensor C4, the first open/close valve V1, the secondopen/close valve V2, the third open/close valve V3, the fourthopen/close valve V4, the fifth open/close valve V5, the sixth open/closevalve V6, the seventh open/close valve V7, the eighth open/close valveV8, the ninth open/close valve V9, and the tenth open/close valve V10.

The detection signals from the sensors Cl, C2, C3, and C4 are input tothe controller 15. Instructed by these detection signals, the controller15 controls the pumps P1, P2, P3, and P4 to operate or stop, andcontrols the rotational direction (normal or reverse) and the rotationalspeed of the pumps. The controller 15 also controls the open/closevalves V1, V2, V3, V4, V5, V6, V7, V8, V9, and V10 to open or close, andcontrols the centrifuge bowl drive unit 14 to operate as required.

As a material of the tubes, for example, thermoplastic elastomers suchas polyvinyl chloride, polyethylene, polypropylene, polyester such asPET and PBT, ethylene-vinyl acetate copolymer (EVA), polyurethane, andpolyester elastomer may be used. Among these materials, particularly,polyvinyl chloride is preferably used. Polyvinyl chloride not only hassufficient ductility and flexibility but also is easy to handle andsuitable to be choked by a clamp or the like.

As a material of the bags, soft polyvinyl chloride including DEHP as aplasticizer or products of polymerization or copolymerization of sucholefins or diolefins as polyolefin, ethylene, propylene, butadiene, andisoprene can be used. Typical examples include ethylene-vinyl acetatecopolymer (EVA), polymer blends formed between EVA and variousthermoplastic elastomers, and arbitrary combinations thereof. Further,PET, PBT, PCGT, or the like can be used. Among these materials,particularly, polyvinyl chloride is preferably used. Such materialhaving high gas permeability is preferable for a container for storingplatelets to improve shelf life of platelets. Therefore, polyolefin orDnDp-plasticized polyvinyl chloride may preferably be used for suchmaterial or a material formed in a thin sheet may preferably be used.

FIG. 15 illustrates a structure of the centrifuge bowl E1. In FIG. 15,the figure is divided by the center line, where the right hand sideillustrates a sectional view and the left hand side illustrates anexternal view in dashed lines. The inflow port E1 a and the outflow portE11 are formed on the non-rotating fixed portion 20 in the bloodcomponent separation device. The fixed portion 20 includes a cover 17and an inflow tube 18 extending downward. These fixed portions rotatablyand integrally support a side wall 21, an outer shell 22, an inner shell23, and a bottom plate 16. The bottom plate 16 is coupled to thecentrifuge bowl drive unit 14 by suctioning so that the rotational forcefrom the centrifuge bowl drive unit 14 can rotate the bottom plate 16.FIG. 15 illustrates a state where whole blood is supplied into thecentrifuge bowl E1 from the inflow port E1 a and blood components areseparated by a centrifugal force.

That is, in the space between the outer shell 22 and the side wall 21from outer side to inner side, in the descending order of specificgravity, a red blood cell layer RBC, a white blood cell layer WBC, abuffy coat layer BC, a platelet layer PLT, and a plasma layer PPP areformed by a centrifugal force. It is difficult to separate the whiteblood cell layer WBC and the platelet layer PLT, because the values oftheir specific gravities are close. Thus, the buffy coat layer BCincluding the white blood cell layer WBC and the platelet layer PLTexists. Typically, the whole blood includes about 55% of plasma PPP,about 43.2% of red blood cells RBC, about 1.35% of white blood cellsWBC, and 0.45% of platelets PLT.

The centrifuge bowl E1 has an outflow passage 19 in the inner peripheryformed somewhat above the middle point of the inflow tube 18. So thatthe plasma layer PPP formed in the inner side of the space formed by theouter shell 22 and the side wall 21 flows out from the centrifuge bowlE1 through the outflow port E1 b.

The operation of the blood component separation device configured asdescribed above is illustrated in flow charts in FIGS. 18 and 19. Theoperation and steps performed in the blood component separation deviceare illustrated in FIGS. 2 to 14. The object of the device is to collecthigh-concentration platelet liquid. The pump outlined with a whiteinside shows that the pump is operating. The pump outlined with a blackinside shows that the pump is not operating. The open/close valveoutlined with a white inside shows that the valve is opened. Theopen/close valve outlined with a black inside shows that the valve isclosed. FIG. 16 is a processing drawing illustrating the operation ofthe blood component separation device in a chronological order.

First, a priming step (S1) illustrated in FIG. 18 is performed. The ACDpump P4 and the first pump P1 are operated to supply ACD liquid, whichprevents blood coagulation, to the centrifuge bowl E1 through the openedfirst open/close valve V1, thereby performing the priming step (S1) ofthe centrifuge bowl E1, the first pump P1, etc. The priming step isperformed to previously apply the ACD liquid on portions in the donortube T1, the first pump P1, the centrifuge bowl E1, etc., which are tomake contact with blood, so that the blood will not coagulate whenintroduced. From the priming step, the centrifuge bowl drive unit 14rotates the centrifuge bowl E1 at a predetermined rotational speed.

When the priming step (S1) is finished, the blood drawing needle 2pierces the blood donor to start drawing of whole blood (S2). FIG. 2illustrates a starting blood drawing step (the first step).

With the blood drawing needle 2 piercing the blood donor, first, theinitial flow blood is collected in the initial flow blood collecting bagY7 in the initial flow blood collecting circuit (see FIG. 1). The branchprovided on the donor tube T1 is initially configured to couple theblood drawing needle 2 and the initial flow blood collecting line 4 (seeFIG. 1). When a predetermined amount of blood is stored in the initialflow blood collecting bag, the initial flow blood collecting line 4 ischoked by the clamp 8 (see FIG. 1) to secure a flow passage toward thefirst blood pump P1 in the donor tube T1.

The ACD pump P4 is operated again to supply the ACD liquid to the donortube T1 so that the ACD liquid is mixed with the whole blood, which isthen supplied to the centrifuge bowl E1. When whole blood is supplied tothe rotating centrifuge bowl E1, the air inside the centrifuge bowl E1(shown in dashed lines) flows out, pushed by the plasma, through theoutflow passage 19 (see FIG. 15) located in the inner periphery of thecentrifuge bowl E1, as illustrated in FIG. 2. The air then flows throughthe opened ninth open/close valve V9 and is stored in the air bag Y4.

In the centrifuge bowl E1, as illustrated in FIG. 15, the supplied wholeblood is separated into components by the centrifugal force generated inthe bowl.

Then when the turbidity sensor C2 detects that the fluid flowing in thetube has changed from air to plasma, the ninth open/close valve V9 isclosed and the second open/close valve V2 is opened to store the plasmaspilled out from the centrifuge bowl E1 in the plasma bag Y1, asillustrated in FIG. 3. Thus the centrifugal separation step (S3) isperformed. As illustrated in FIG. 15, first, only the plasma comes outfrom the centrifuge bowl E1.

Then when a certain amount of plasma (30 ml for the working example) isstored in the plasma bag Y1 (S4: YES), the third open/close valve V3 isopened, the second blood pump P2 is operated, and the fourth open/closevalve V4 is opened to draw whole blood from the blood donor. Along withthis, the whole blood is mixed with the plasma stored in the plasma bagY1 and supplied to the centrifuge bowl E1, as illustrated in FIG. 4. Athird step (critical flow step) S5 is thus performed. These areperformed in a critical flow period TE illustrated in FIG. 16.

When the interface sensor C4 detects that the interface between thebuffy coat layer BC and the red blood cell layer RBC in FIG. 15 has cometo a predetermined position (S6: YES), the second open/close valve V2,the third open/close valve V3, and the fourth open/close valve V4 arekept opened with the second blood pump P2 kept operating as illustratedin FIG. 5. The plasma in the plasma bag Y1 flows through the thirdopen/close valve V3, the second blood pump P2, the fourth open/closevalve V4, the centrifuge bowl E1, and the second open/close valve V2 toreturn to the plasma bag Y1. A circulation step (the fourth step) in thecirculation/acceleration step is thus performed (S9, S12). The firstopen/close valve V1 is closed to prevent the drawn whole blood fromflowing into the centrifuge bowl E1. These are performed in acirculation period TF illustrated in FIG. 16.

At the same time, whether the present cycle is the last cycle isdetermined. When the present cycle is not the last cycle (S7: NO), thesixth open/close valve V6 is opened, with the first blood pump P1 keptoperating, to store the drawn whole blood in the temporary storage bagY2 (S11). In other words, the drawn whole blood is stored in thetemporary storage bag Y2 so that the drawing of whole blood can becontinued. Drawing of whole blood is continued until thecirculation/acceleration step finishes, a predetermined time haselapsed, or a predetermined amount has been drawn. In the last cycle(S7: YES), the first blood pump P1 stops operating to stop blood drawing(S8).

In the circulation step in the circulation/acceleration step of theworking example, the circulation speed is set higher than that of thecritical flow step so as that the plasma circulates at a speed of about100 ml/min, thereby flowing through the centrifuge bowl E1 within 30 to40 seconds. In this manner, the concentration of particulates in thebuffy coat layer BC in FIG. 15 decreases, whereby the white blood celllayer WBC having a larger specific gravity than platelets sediments inthe outer side of the buffy coat layer BC. That is, the platelet layerPLT and the white blood cell layer WBC can further distinctly beseparated.

Then after the circulation step performed for a certain period of time,an acceleration step (the fifth step) in the circulation/accelerationstep illustrated in FIG. 6 starts. In the acceleration step, therotational speed of the second blood pump P2 is controlled to graduallyincrease, thereby gradually increasing the flow rate of plasmas. In theworking example, the flow rate of plasma is raised from an initial flowrate of 100 ml/min until platelets flows out. This is performed in anacceleration period TG illustrated in FIG. 16. FIG. 18 illustrates thecirculation/acceleration step (S9) representing the circulation step andthe acceleration step.

In the acceleration step, the platelets PLT are forced upward andthereby flow out of the centrifuge bowl E1 through the outflow passage19, as illustrated in FIG. 15. During this acceleration, the white bloodcell layer WBC and the red blood cell layer RBC having large specificgravities, therefore receiving greater effect of centrifugal force, willnot flow out from the outflow passage 19.

FIG. 17 illustrates changes in concentrations of platelets, white bloodcells, and red blood cells flowing out. The horizontal axis representselapsed time during collecting platelets, and the vertical axisrepresents concentrations of blood cell components flowing out. First,platelets flow out (outflow period TA). In this period, the outflow rateof platelets gradually increases and, after peaking at the maximum flowrate, gradually decreases. Similarly, the outflow rate of white bloodcells gradually increases and, after peaking at the maximum flow rate,gradually decreases.

FIG. 19 illustrates S9 in detail with a flowchart showing the operationof the blood component separation device. The outflow period TA ofplatelets can be divided into three periods, that is, alow-concentration period TB, which comes first, where low-concentrationplatelet liquid flows out, a high-concentration period TC, following theTB period, where high-concentration platelet liquid flows out, and alow-concentration period TD, following the TC period, wherelow-concentration platelet liquid flows out again. Low-concentrationplatelet liquid is not necessary for obtaining high-concentrationplatelet liquid.

In the working example, in the acceleration step as illustrated in FIG.6, when the turbidity sensor C2 detects platelets, that is, when it isdetermined that the present period is the TB period (S21: YES), thesecond open/close valve V2 is closed and the fifth open/close valve V5is opened to store platelet liquid flowing out during thelow-concentration period TB in FIG. 17 in the temporary storage bag Y2(S22). Since the whole blood also flows into the temporary storage bagY2 to be stored, the low-concentration platelet liquid is stored in thetemporary storage bag Y2 mixed with the whole blood. Since the firstblood pump P1 is kept operating, the whole blood drawn from the blooddonor is continuously stored in the temporary storage bag Y2. Note that,the temporary storage bag Y2 serves as a buffy coat bag as well as awhole blood bag.

When the turbidity sensor C2 detects that the concentration of plateletliquid is high, it is determined that the present period is the TCperiod (S23: YES), and the fifth open/close valve V5 is closed and theeighth open/close valve V8 is opened as illustrated in FIG. 7. In thismanner, the high-concentration platelet liquid flowing out during thehigh-concentration period TC can be stored in the platelet intermediatebag Y3 (S24).

If the present cycle is not the last cycle (S7: NO), the first bloodpump P1 is kept operating so that the whole blood drawn from the blooddonor continuously flows through the sixth open/close valve V6 and isstored in the temporary storage bag Y2.

When the turbidity sensor C2 detects that the turbidity of platelets isbelow a predetermined value, it is determined that the present period isthe TD period (S25: YES), and the eighth open/close valve V8 is closedto block the low-concentration platelet liquid from flowing into theplatelet intermediate bag Y3 and the fifth open/close valve V5 isopened, as illustrated in FIG. 8. In this manner, the low-concentrationplatelet liquid flowing out during the low-concentration period TD canbe stored again in the temporary storage bag Y2 (S26).

If the present cycle is not the last cycle (S7: NO), the first bloodpump P1 is kept operating so that the whole blood drawn from the blooddonor continuously flows through the sixth open/close valve V6 and isstored in the temporary storage bag Y2.

Then when the turbidity sensor C2 detects that the turbidity ofplatelets is below a predetermined value, it is determined that the TDperiod is finished (S27: YES), or the outflow of platelets is finished,and the step proceeds to the blood returning step illustrated in FIG. 9(S10, S13).

In the blood returning step, the centrifuge bowl E1 stops rotation, thesixth open/close valve V6 and the fifth open/close valve V5 are closed,the first open/close valve V1 and the ninth open/close valve V9 areopened, and the first blood pump P1 is reversely rotated, whereby thereturning of the blood remaining in the centrifuge bowl E1 to the blooddonor starts. The first blood pump P1 is reversely operated at doublethe rotational speed of the normal rotation to shorten the time of bloodreturning. Further, as required, the second blood pump P2 is operated toreturn the excessive plasma stored in the plasma bag Y1.

When the blood returning finishes, and if the present cycle is the lastcycle (S7: YES), the entire process is finished. When the finished cycleis not the last cycle (S7: NO), the centrifuge bowl E1 starts rotatingas illustrated in FIG. 10, and the first blood pump P1 starts normalrotation again to perform blood drawing. The air inside the centrifugebowl E1 (shown in dashed lines) flows out, pushed by the plasma, throughthe outflow passage 19 located in the inner periphery of the centrifugebowl E1. The air then flows through the opened ninth open/close valve V9and is stored in the air bag Y4. The seventh open/close valve V7 isopened and the second blood pump P2 is operated to allow the bloodstored in the temporary storage bag Y2 to flow through the fourthopen/close valve V4 into the centrifuge bowl E1 together with the drawnwhole blood (S14). The third open/close valve V3 is closed to block thefluid from flowing into the plasma bag Y1.

Then when the turbidity sensor C2 detects that the fluid flowing in thetube has changed from air to plasma, the ninth open/close valve V9 isclosed and the second open/close valve V2 is opened to store the plasmaspilled out from the centrifuge bowl E1 in the plasma bag Y1, asillustrated in FIG. 11.

Then when it is confirmed that the whole blood in the temporary storagebag Y2 has returned to the centrifuge bowl E1 and that a predeterminedamount of plasma is stored in the plasma bag Y1 (S4: YES), the seventhopen/close valve V7 is closed with the second blood pump P2 keptoperating, and the third open/close valve V3 is opened to mix the plasmastored in the plasma bag Y1 with the whole blood and to supply themixture of the plasma and the whole blood to the centrifuge bowl E1,whereby the critical flow step of plasma starts as illustrated in FIG.12 (the same state as in FIG. 4). The step proceeds to the stepillustrated in FIG. 5 (circulation step).

This cycle is repeated, typically three or four times, until apredetermined amount of platelets PLT is obtained. When the operationfinishes with three cycles, for example, blood drawing is performed inparallel in a circulation period TF2 and an acceleration period TG2 inthe second cycle to store whole blood in the temporary storage bag Y2.Then during blood drawing in the third cycle, the blood in the temporarystorage bag Y2 is mixed with whole blood and supplied to the centrifugebowl E1. Further, in a circulation period TF3 and an acceleration periodTG3 in the third cycle, blood drawing is not performed. This is becausethere is no fourth cycle.

When the operation is to finish with three cycles, blood drawingfinishes when the blood drawing needle 2 is removed from the blood donorafter completion of the blood returning in the third cycle.

Then, the third blood pump P3 is operated to inject a suitable amount ofplatelet reserve liquid into the platelet intermediate bag Y3 from abottle needle 10 coupled to the platelet reserve liquid bottle. Asillustrated in FIG. 13, the tenth open/close valve V10 is then opened toinject the high-concentration platelet liquid stored in the plateletintermediate bag Y3 into the platelet bag Y5 through the white bloodcell removal filter 11. In this process, the air in the platelet bag Y5flows into the air bag Y6.

After confirming that the high-concentration platelet liquid stored inthe platelet intermediate bag Y3 has completely been taken out, thethird blood pump P3 is operated to inject the platelet reserve liquidremaining in the platelet reserve liquid bottle into the platelet bagY5, through the bottle needle 10 coupled to the platelet reserve liquidbottle, the sterilizing filter 9, and the white blood cell removalfilter 11, as illustrated in FIG. 14. In this manner, already filteredhigh-concentration platelet liquid remaining on the white blood cellremoval filter 11 is recovered. Then, two tubes of the platelet bag aresealed. In this manner, the platelet bag Y5 storing high-concentrationplatelet liquid is prepared.

According to the working example, as described above in detail, (1)blood component separation device includes a centrifuge bowl E1 forseparating a predetermined blood component from blood and a container(plasma bag Y1, platelet intermediate bag Y3) for containing thecentrifugally separated predetermined blood component, and performs (a)centrifugal separation step of introducing the whole blood drawn from ablood donor into the centrifuge bowl E1 with a first blood pump P1 toseparate the whole blood into a plurality of blood components, (b)critical flow step (circulation flow step of the present invention) ofintroducing the plasma (the first blood component), among centrifugallyseparated blood components, stored in the plasma bag Y1 (firstcontainer) into the centrifuge bowl E1 together with whole blood, and(c) circulation/acceleration step of introducing, after separating theplasma in the critical flow step, only the plasma stored in the plasmabag Y1 into the centrifuge bowl E1 with the second blood pump P2 tocirculate the plasma for a predetermined period of time, and increasingthe circulation speed in the centrifuge bowl E1 to separate and collectplatelets (the second blood component). The blood component separationdevice is characterized in that the whole blood drawn from the blooddonor is temporarily stored in the temporary storage bag Y2 (temporarystorage container) during at least a period of time in thecirculation/acceleration step, one of the tubes coupled to the temporarystorage bag Y2, which is the tube T11 b, is coupled to an outlet port E1b of the centrifuge bowl E1 via the tube T11 a, the tube T15, and thetube T5, and the other one of the tubes, which is the tube T12, iscoupled, via the tube T13 b and the tube T13 a, between the plasma bagY1 and the second blood pump P2. Moreover, (2) blood componentseparation device according to (1) is preferably characterized in that,in the centrifugal separation step in the following cycle, at leasteither the whole blood or the low-concentration platelet liquid storedin the temporary storage bag Y2 in the previous cycle is introduced intothe centrifuge bowl E1 by the second blood pump P2, so that either ofthe whole blood or the low-concentration platelet liquid stored in theprevious cycle can quickly and surely be introduced into the centrifugebowl E1.

(3) The blood component separation device according to (1) or (2) ispreferably characterized in that the other tube T12 is branched and theone of the branched tube is coupled, via the tube T13 b, the tube T13 a,and the tube T2, to the outlet port of the first blood pump P1, and thetwo tubes T13 b and T14 a branched from the other tube T12 are coupledto the sixth open/close valve V6 and the seventh open/close valve V7,respectively, so that at least either the whole blood or thelow-concentration second blood component stored in the temporary storagebag Y2 can be introduced into the centrifugal separator E1 by using thesecond blood pump P2 without providing any additional blood pump. Thus,the device need not be large in size and the cost can be reduced.Furthermore, compared to a device using a difference in elevationinstead of a blood pump, at least either the whole blood or thelow-concentration second blood component stored in the temporary storagebag Y2 can be introduced into the centrifugal separator E1 in a shorttime by using the blood pump.

(4) The blood component separation device according to any one of (1) to(3) performs (d) blood returning step, performed after collectingplatelets in the circulation/acceleration step, of returning to theblood donor the blood component that is not collected, and ischaracterized in that the whole blood stored in the temporary storagebag Y2 (temporary storage container) is introduced, in the centrifugalseparation step in the following cycle, into the centrifuge bowl E1together with the whole blood drawn in the following cycle, where thesteps (a) to (d) constitute one cycle. In this manner, the whole bloodcan be drawn from the blood donor in parallel with thecirculation/acceleration step in the first cycle (the present cycle).Thus, the time for drawing whole blood in the second cycle (thefollowing cycle) and therefore the total time for the total process canbe reduced, thereby reducing the binding time of the blood donor.

For example, typical time periods in one cycle are about twelve minutesfor blood drawing (centrifugal separation step + critical flow step), 30to 40 seconds for the circulation step in the circulation/accelerationstep, 20 to 30 seconds for the acceleration step in thecirculation/acceleration step, and about five minutes for the bloodreturning. According to the present invention, since blood drawing isperformed for about one minute in the first cycle, the blood drawingtime in the second cycle can be reduced by one minute to about elevenminutes. Similarly, when total of three cycles are performed, the blooddrawing time in the third cycle can be reduced by one minute to abouteleven minutes.

For a blood donor, the amount of blood circulating outside the bodyincreases, though it may not be a problem for 90% of blood donors. Thedonor may be checked in advance to see if there is a problem to increasethe amount of blood circulating outside the body. If there may be aproblem, a switching unit can be used so as not to perform the drawingof whole blood in parallel with the circulation/acceleration step in thefirst cycle (the present cycle), but to perform the drawing of wholeblood in the second cycle (the following cycle) after returning blood.It goes without saying that the drawing of whole blood for the followingcycle is not performed in the last cycle, because there is no cyclefollowing the last cycle.

(5) The blood component separation device according to any one of (1) to(4) is preferably characterized in that the circulation/accelerationstep includes a first collecting step of transferring a portion ofplatelet liquid (second blood component) with low-concentration(low-concentration second blood component) to a temporary storage bag Y2and a second collecting step of collecting a portion of platelet liquidwith high-concentration (high-concentration second blood component), andthe low-concentration platelet liquid transferred to the temporarystorage bag Y2 and the whole blood collected in the temporary storagebag Y2 in the following cycle are introduced into the centrifuge bowl E1together with the whole blood drawn in a following cycle. Therefore, thedevice can be used for the BC recycling for obtaining platelets withhigh-concentration, and since the whole blood can be drawn from theblood donor in parallel with the circulation/acceleration step in thefirst cycle (the present cycle), the time for drawing whole blood in thesecond cycle (the following cycle) and therefore the time for the totalprocess can be reduced, thereby reducing the binding time of the blooddonor.

(6) The blood component separation device according to (5) preferablyincludes the second container for temporarily storing thelow-concentration platelet liquid in the circulation/acceleration step,and is characterized in that the second container also serves as thetemporary storage bag Y2. Therefore, an additional second container isnot required so that the device need not be made large in size, andsince a special disposable second container is not necessary, the costcan be reduced.

The working examples of the present invention are described above indetail. The present invention is not limited to the aforementionedworking examples and can be used for various applications. For example,in the working example, the temporary storage bag Y2 serves as a buffycoat bag as well as a whole blood bag, although the buffy coat bag mayindividually be provided in parallel with the whole blood bag. In theworking example, the drawing of whole blood is performed in parallelthroughout the entire period of the circulation/acceleration step,although the drawing of whole blood may be performed in parallel with acertain time period. In the working example, the drawing of whole bloodis performed in parallel with the circulation/acceleration step,although the switching unit may be provided to the blood componentseparation device so as not to draw whole blood in parallel but to drawwhole blood in a conventional manner.

REFERENCE SIGNS LIST

14 centrifuge bowl drive unit

E1 centrifuge bowl

Y1 plasma bag (first container)

Y2 temporary storage bag (second container)

Y3 platelet intermediate bag (third container)

Y4, Y6 air bag

Y5 platelet bag

C2 turbidity sensor

C4 interface sensor

P1 first blood pump

P2 second blood pump

P3 third blood pump

P4 ACD pump

PPP plasma (first blood component)

PLT platelet (second blood component)

WBC white blood cell

BC buffy coat

RBC red blood cell

1. A disposable set of containers for use on a blood componentcentrifugal separator having a first pump, a second pump and acentrifuge rotor, the disposable set comprising: a separation containeradapted to be mounted on the centrifuge rotor and having an inlet portand an outlet port; a tube in fluid communication with a source of wholeblood drawn from a blood donor and in further fluid communication withthe separation container and adapted to engage the first pump, a firstcontainer for receiving a predetermined first blood component, amongcentrifugally separated blood components, together with whole blood,said first container being in fluid communication with the outlet portof said separation chamber and with the inlet port of said separationchamber, and a second tube adapted to engage the second pump and influid communication with said first container and said inlet port ofsaid separation container, a temporary storage container wherein wholeblood drawn from the blood donor is temporarily stored, and a third tubecoupled to the temporary storage container further coupled to the outletport of the separation container and a fourth tube also coupled to thetemporary storage container and further coupled between the firstcontainer and the second tube.
 2. The disposable set of containersaccording to claim 1 further comprising a fifth tube in fluidcommunication with said third tube and said first tube such that saidsecond tube is connected to said first tube between said fifth tube andsaid inlet port of said separation chamber.
 3. The disposable set ofclaim 1 wherein said first container is coupled through a singleinlet-outlet tube to a coupling tube in fluid communication with saidfirst container and said inlet port of said separation container.
 4. Thedisposable set of claim 3 further comprising an auxiliary firstcontainer, said auxiliary first container having an inlet in fluidcommunication with said outlet port of the separation chamber and anoutlet in fluid communication with said single inlet-outlet tube.
 5. Thedisposable set of claim 1 further comprising a third container adaptedto receive platelets, said third container being in fluid communicationwith the outlet port of the separation chamber.
 6. The disposable set ofclaim 5 further comprising a fourth container for receiving purifiedplatelets and a white blood cell filter, third container being in fluidcommunication with an inlet of said white blood cell filter and saidfourth container being in fluid communication with an outlet of saidwhite blood cell filter.
 7. The disposable set of claim 6 furthercomprising means for adding liquid to said set between said thirdcontainer and said fourth container.
 8. The disposable set of claim 1further comprising means for adding anticoagulant to whole blood orblood components in the disposable set.
 9. The disposable set of claim 1further comprising means for taking a sample of blood or bloodcomponents in the disposable set.